Egon
Epic Contributor
There is always a dip stick hole. /forums/images/graemlins/grin.gif
Egon /forums/images/graemlins/grin.gif
Egon /forums/images/graemlins/grin.gif
smoke
- Thread starter Pauly
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Egon
Epic Contributor
There is always a dip stick hole. /forums/images/graemlins/grin.gif
Egon /forums/images/graemlins/grin.gif
Egon /forums/images/graemlins/grin.gif
JohnS
Platinum Member
The dipstick on the Y385 is a rod into a threaded cap. Dipstick screws down. It may not be 100% airtight, but it is nothing like a typical push-in car dipstick.
There could be other outlets for crankcase pressure, though.
There could be other outlets for crankcase pressure, though.
JohnS
Platinum Member
The dipstick on the Y385 is a rod into a threaded cap. Dipstick screws down. It may not be 100% airtight, but it is nothing like a typical push-in car dipstick.
There could be other outlets for crankcase pressure, though.
There could be other outlets for crankcase pressure, though.
RonMar
Elite Member
</font><font color="blue" class="small">(
I believe this mainly an emissions function. Blowby will have very little unburned fuel, same as what is exiting via exhaust. Never heard of any 70's car motor blowing because it didn't have pcv, and gas vapors are much more combustable than diesel. All they had were foam breathers in valve covers. At least not at stock rpms.
)</font>
What you say about blowby having very little unburned fuel is correct for gas engines. In diesels, they will pass unburned fuel past the rings and into the oil. On lightly loaded engines, you can actually run into problems with the lube oil being diluted by the ammount of diesel fuel making it into the oil. On a hot engine, this lighter diesel can make it back into vapor form and reach combustible levels if not removed. On all the large marine diesels I have operated, they all had crankcase exhausters(large electric blowers) that kept the crankcase under vacume. This level of vacume was monitored electronically. You could not start the engine and the engine would shutdown automatically if there was not enough vacume in the case. On my last ship while steaming across the equator, we would be running near max temperatures and near max load and the added blowby combined with vacume leaks around the engine would keep us very near the vacume shutdown point on the engines.
Crankcase explosion was also regularly on our required drill scenario listing as it tends to spread hot lube oil all over the engine room when it blows the crankcase inspection ports off. I have never personally experienced one but they do happen.
I believe this mainly an emissions function. Blowby will have very little unburned fuel, same as what is exiting via exhaust. Never heard of any 70's car motor blowing because it didn't have pcv, and gas vapors are much more combustable than diesel. All they had were foam breathers in valve covers. At least not at stock rpms.
)</font>
What you say about blowby having very little unburned fuel is correct for gas engines. In diesels, they will pass unburned fuel past the rings and into the oil. On lightly loaded engines, you can actually run into problems with the lube oil being diluted by the ammount of diesel fuel making it into the oil. On a hot engine, this lighter diesel can make it back into vapor form and reach combustible levels if not removed. On all the large marine diesels I have operated, they all had crankcase exhausters(large electric blowers) that kept the crankcase under vacume. This level of vacume was monitored electronically. You could not start the engine and the engine would shutdown automatically if there was not enough vacume in the case. On my last ship while steaming across the equator, we would be running near max temperatures and near max load and the added blowby combined with vacume leaks around the engine would keep us very near the vacume shutdown point on the engines.
Crankcase explosion was also regularly on our required drill scenario listing as it tends to spread hot lube oil all over the engine room when it blows the crankcase inspection ports off. I have never personally experienced one but they do happen.
RonMar
Elite Member
</font><font color="blue" class="small">(
I believe this mainly an emissions function. Blowby will have very little unburned fuel, same as what is exiting via exhaust. Never heard of any 70's car motor blowing because it didn't have pcv, and gas vapors are much more combustable than diesel. All they had were foam breathers in valve covers. At least not at stock rpms.
)</font>
What you say about blowby having very little unburned fuel is correct for gas engines. In diesels, they will pass unburned fuel past the rings and into the oil. On lightly loaded engines, you can actually run into problems with the lube oil being diluted by the ammount of diesel fuel making it into the oil. On a hot engine, this lighter diesel can make it back into vapor form and reach combustible levels if not removed. On all the large marine diesels I have operated, they all had crankcase exhausters(large electric blowers) that kept the crankcase under vacume. This level of vacume was monitored electronically. You could not start the engine and the engine would shutdown automatically if there was not enough vacume in the case. On my last ship while steaming across the equator, we would be running near max temperatures and near max load and the added blowby combined with vacume leaks around the engine would keep us very near the vacume shutdown point on the engines.
Crankcase explosion was also regularly on our required drill scenario listing as it tends to spread hot lube oil all over the engine room when it blows the crankcase inspection ports off. I have never personally experienced one but they do happen.
I believe this mainly an emissions function. Blowby will have very little unburned fuel, same as what is exiting via exhaust. Never heard of any 70's car motor blowing because it didn't have pcv, and gas vapors are much more combustable than diesel. All they had were foam breathers in valve covers. At least not at stock rpms.
)</font>
What you say about blowby having very little unburned fuel is correct for gas engines. In diesels, they will pass unburned fuel past the rings and into the oil. On lightly loaded engines, you can actually run into problems with the lube oil being diluted by the ammount of diesel fuel making it into the oil. On a hot engine, this lighter diesel can make it back into vapor form and reach combustible levels if not removed. On all the large marine diesels I have operated, they all had crankcase exhausters(large electric blowers) that kept the crankcase under vacume. This level of vacume was monitored electronically. You could not start the engine and the engine would shutdown automatically if there was not enough vacume in the case. On my last ship while steaming across the equator, we would be running near max temperatures and near max load and the added blowby combined with vacume leaks around the engine would keep us very near the vacume shutdown point on the engines.
Crankcase explosion was also regularly on our required drill scenario listing as it tends to spread hot lube oil all over the engine room when it blows the crankcase inspection ports off. I have never personally experienced one but they do happen.
JohnS
Platinum Member
Ron,
Thanks for additional explaination. I won't argue with you Navy guys! /forums/images/graemlins/wink.gif Those diesels can be huge! I think I can rationalize why that may be, but I will chew on it some more, before posting any more JohnS theory. /forums/images/graemlins/blush.gif
Thanks for additional explaination. I won't argue with you Navy guys! /forums/images/graemlins/wink.gif Those diesels can be huge! I think I can rationalize why that may be, but I will chew on it some more, before posting any more JohnS theory. /forums/images/graemlins/blush.gif
JohnS
Platinum Member
Ron,
Thanks for additional explaination. I won't argue with you Navy guys! /forums/images/graemlins/wink.gif Those diesels can be huge! I think I can rationalize why that may be, but I will chew on it some more, before posting any more JohnS theory. /forums/images/graemlins/blush.gif
Thanks for additional explaination. I won't argue with you Navy guys! /forums/images/graemlins/wink.gif Those diesels can be huge! I think I can rationalize why that may be, but I will chew on it some more, before posting any more JohnS theory. /forums/images/graemlins/blush.gif
greg_g
Super Member
- Joined
- Dec 18, 2003
- Messages
- 6,126
- Location
- Western Kentucky
- Tractor
- JD3720 Cab, 300X loader with 4-in-1 bucket
</font><font color="blue" class="small">( I have seen the posts greg mentions. I couldn't come up with how it would effect oil pressure, either. Only thought was what soundguy mentioned. Anyone with a y385 can go do a test and kink their hose to see if it does effect oil pressure.
Let me throw this out for discussion: If the inlet crankcase filter is totally plugged up, and then the plastic hose became kinked, would that build up enough pressure or vacuum to possibly effect oil pressure? It would seem to me, that it would have to create allot of pressure, but not sure. Thoughts??? )</font>
Wish I still had mine to try your little experiment, but there are still plenty of members that might volunteer. I'm straying off topic here, but hopefully not far enough to distract attention from Pauly's original issue.
I do know that the OE oil pressure sending unit represents ground to the OE oil pressure gauge. Internal to the OPSU is a diaphram that - when at rest - presents roughly a zero ohm path to the engine block and eventually to the negative post of the battery. Movement of that diaphram represents resistance to ground, which is reflected by needle movement in the gauge. The degree to which moving oil presses on the diaphram increases or decreases the resistance to ground, reflected then by higher or lower oil pressure indications on the gauge.
That much is known, the following is a SWAG. I'm having a little trouble with the fact that the clear plastic tubes on my Jinmas never got dirty inside, as you might expect if they were carrying oil/fuel contaminated fumes. Therefore I'm going to go a different route from RonMar with this, suggesting that the clear vinyl tube is just a pressure equalizer. And that the oil breather bolted to the lower side of the block truly breathes; that is, permits the passage of air in both directions. Inhale/exhale, depending upon the difference in atmospheric pressure inside and outside the crankcase. And that the screen inside just catches the airborne when the crankcase is "exhaling". The clear tube then, would be unrelated to the breather - merely making sure that pressures under the valve cover were roughly equal to that in the crankcase. An equalizer tube.
OK. The engine's now breathing, and the oil pressure's currently constant. So now let's kink that clear tube, so that the pressure on top is no longer the same as the pressure below. I could see this situation lowering the atmospheric pressure inside the crankcase, without lowering the ACTUAL oil pressure. But at the same time this negative pressure could pull back on the OPSU diaphram, changing the resistance to ground and giving a false representation of lowered oil pressure on the gauge. Straightening out the kink equalizes the pressure again, removing the negative pressure force from the diaphram - oil pressure indication returns to normal.
Please remember a lot of this is SWAG, so please don't beat me up too hard if I've overlooked something obvious.
//greg//
Let me throw this out for discussion: If the inlet crankcase filter is totally plugged up, and then the plastic hose became kinked, would that build up enough pressure or vacuum to possibly effect oil pressure? It would seem to me, that it would have to create allot of pressure, but not sure. Thoughts??? )</font>
Wish I still had mine to try your little experiment, but there are still plenty of members that might volunteer. I'm straying off topic here, but hopefully not far enough to distract attention from Pauly's original issue.
I do know that the OE oil pressure sending unit represents ground to the OE oil pressure gauge. Internal to the OPSU is a diaphram that - when at rest - presents roughly a zero ohm path to the engine block and eventually to the negative post of the battery. Movement of that diaphram represents resistance to ground, which is reflected by needle movement in the gauge. The degree to which moving oil presses on the diaphram increases or decreases the resistance to ground, reflected then by higher or lower oil pressure indications on the gauge.
That much is known, the following is a SWAG. I'm having a little trouble with the fact that the clear plastic tubes on my Jinmas never got dirty inside, as you might expect if they were carrying oil/fuel contaminated fumes. Therefore I'm going to go a different route from RonMar with this, suggesting that the clear vinyl tube is just a pressure equalizer. And that the oil breather bolted to the lower side of the block truly breathes; that is, permits the passage of air in both directions. Inhale/exhale, depending upon the difference in atmospheric pressure inside and outside the crankcase. And that the screen inside just catches the airborne when the crankcase is "exhaling". The clear tube then, would be unrelated to the breather - merely making sure that pressures under the valve cover were roughly equal to that in the crankcase. An equalizer tube.
OK. The engine's now breathing, and the oil pressure's currently constant. So now let's kink that clear tube, so that the pressure on top is no longer the same as the pressure below. I could see this situation lowering the atmospheric pressure inside the crankcase, without lowering the ACTUAL oil pressure. But at the same time this negative pressure could pull back on the OPSU diaphram, changing the resistance to ground and giving a false representation of lowered oil pressure on the gauge. Straightening out the kink equalizes the pressure again, removing the negative pressure force from the diaphram - oil pressure indication returns to normal.
Please remember a lot of this is SWAG, so please don't beat me up too hard if I've overlooked something obvious.
//greg//
greg_g
Super Member
- Joined
- Dec 18, 2003
- Messages
- 6,126
- Location
- Western Kentucky
- Tractor
- JD3720 Cab, 300X loader with 4-in-1 bucket
</font><font color="blue" class="small">( I have seen the posts greg mentions. I couldn't come up with how it would effect oil pressure, either. Only thought was what soundguy mentioned. Anyone with a y385 can go do a test and kink their hose to see if it does effect oil pressure.
Let me throw this out for discussion: If the inlet crankcase filter is totally plugged up, and then the plastic hose became kinked, would that build up enough pressure or vacuum to possibly effect oil pressure? It would seem to me, that it would have to create allot of pressure, but not sure. Thoughts??? )</font>
Wish I still had mine to try your little experiment, but there are still plenty of members that might volunteer. I'm straying off topic here, but hopefully not far enough to distract attention from Pauly's original issue.
I do know that the OE oil pressure sending unit represents ground to the OE oil pressure gauge. Internal to the OPSU is a diaphram that - when at rest - presents roughly a zero ohm path to the engine block and eventually to the negative post of the battery. Movement of that diaphram represents resistance to ground, which is reflected by needle movement in the gauge. The degree to which moving oil presses on the diaphram increases or decreases the resistance to ground, reflected then by higher or lower oil pressure indications on the gauge.
That much is known, the following is a SWAG. I'm having a little trouble with the fact that the clear plastic tubes on my Jinmas never got dirty inside, as you might expect if they were carrying oil/fuel contaminated fumes. Therefore I'm going to go a different route from RonMar with this, suggesting that the clear vinyl tube is just a pressure equalizer. And that the oil breather bolted to the lower side of the block truly breathes; that is, permits the passage of air in both directions. Inhale/exhale, depending upon the difference in atmospheric pressure inside and outside the crankcase. And that the screen inside just catches the airborne when the crankcase is "exhaling". The clear tube then, would be unrelated to the breather - merely making sure that pressures under the valve cover were roughly equal to that in the crankcase. An equalizer tube.
OK. The engine's now breathing, and the oil pressure's currently constant. So now let's kink that clear tube, so that the pressure on top is no longer the same as the pressure below. I could see this situation lowering the atmospheric pressure inside the crankcase, without lowering the ACTUAL oil pressure. But at the same time this negative pressure could pull back on the OPSU diaphram, changing the resistance to ground and giving a false representation of lowered oil pressure on the gauge. Straightening out the kink equalizes the pressure again, removing the negative pressure force from the diaphram - oil pressure indication returns to normal.
Please remember a lot of this is SWAG, so please don't beat me up too hard if I've overlooked something obvious.
//greg//
Let me throw this out for discussion: If the inlet crankcase filter is totally plugged up, and then the plastic hose became kinked, would that build up enough pressure or vacuum to possibly effect oil pressure? It would seem to me, that it would have to create allot of pressure, but not sure. Thoughts??? )</font>
Wish I still had mine to try your little experiment, but there are still plenty of members that might volunteer. I'm straying off topic here, but hopefully not far enough to distract attention from Pauly's original issue.
I do know that the OE oil pressure sending unit represents ground to the OE oil pressure gauge. Internal to the OPSU is a diaphram that - when at rest - presents roughly a zero ohm path to the engine block and eventually to the negative post of the battery. Movement of that diaphram represents resistance to ground, which is reflected by needle movement in the gauge. The degree to which moving oil presses on the diaphram increases or decreases the resistance to ground, reflected then by higher or lower oil pressure indications on the gauge.
That much is known, the following is a SWAG. I'm having a little trouble with the fact that the clear plastic tubes on my Jinmas never got dirty inside, as you might expect if they were carrying oil/fuel contaminated fumes. Therefore I'm going to go a different route from RonMar with this, suggesting that the clear vinyl tube is just a pressure equalizer. And that the oil breather bolted to the lower side of the block truly breathes; that is, permits the passage of air in both directions. Inhale/exhale, depending upon the difference in atmospheric pressure inside and outside the crankcase. And that the screen inside just catches the airborne when the crankcase is "exhaling". The clear tube then, would be unrelated to the breather - merely making sure that pressures under the valve cover were roughly equal to that in the crankcase. An equalizer tube.
OK. The engine's now breathing, and the oil pressure's currently constant. So now let's kink that clear tube, so that the pressure on top is no longer the same as the pressure below. I could see this situation lowering the atmospheric pressure inside the crankcase, without lowering the ACTUAL oil pressure. But at the same time this negative pressure could pull back on the OPSU diaphram, changing the resistance to ground and giving a false representation of lowered oil pressure on the gauge. Straightening out the kink equalizes the pressure again, removing the negative pressure force from the diaphram - oil pressure indication returns to normal.
Please remember a lot of this is SWAG, so please don't beat me up too hard if I've overlooked something obvious.
//greg//